Synthesis, DMF Sensing and Proton Conduction of a Two-Dimensional Metal-Organic Framework

Abstract

A two-dimensional layered metal-organic framework, [Eu(C26H15NO4)Cl]n (EuCDDB), was synthesized by the reaction of EuCl3• 6H2O and 4,4'-(9H-carbazole-3,6-diyl)dibenzoic acid (H2CDDB) through one-pot solvothermal process, and characterized by several technologies of single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectrum.The crystal structure reveals that hydrogen bonding interaction happens between NH groups and coordinated chloride ions from the adjacent coordination layers, meanwhile, well-opened one-dimensional channel allows the accommodation of water molecules.These characteristics endow EuCDDB with a considerable proton conductivity of 3.70 × 10 -6 S cm -1 under 90 °C and relative humidity of 90%.In addition, EuCDDB also exhibits turn-on luminescent sensing on DMF molecules by enhanced Eu 3+ red emission resulting from efficient ligand-to-metal energy transfer process.